题解 | 计算某字符出现次数

#include <iostream>
#include <string>
using namespace std;
int getCharCount(string str, char ch, int index);

int main() {
    string a;
    getline(cin, a);
    char b;
    cin >> b;

    int count = getCharCount(a, b, 0);
    if (b >= 'a' && b <= 'z') {
        count += getCharCount(a, b-32, 0);
    } else if (b >= 'A' && b <= 'Z') {
        count += getCharCount(a, b+32, 0);
    }
    cout << count;
}

int getCharCount(string str, char ch, int index)
{
    int count = 0;
    int n = str.find(ch, index);
    if (-1 != n) {
        count = getCharCount(str, ch, n+1) + 1;
    }
    return count;
}
// 64 位输出请用 printf("%lld")